Y by
Let
be a sharp-angled triangle of circumcenter
and let
be the feet of altitudes on the sides
,
,
, respectively. Let
be the circumcircle of
, let
is the circle of
and let
be a variable point about
. Consider a circle tangent internally to
at by
and tangent externally the
at
. Prove that the line
passes through a fixed point on the line
.

















